University officials credit ISU's low rate to financial counseling and an emphasis on limited borrowing. ISU officials say they also have well-educated graduates who land jobs in their fields that enable them to make payments.

The Education Department's recently released figures are based on the percentage of students whose repayment was to begin between Oct. 1, 2008, and Sept. 30, 2009, and who defaulted before Sept. 30, 2011.